11.4 - Retractable Hardtop (RH) 33 A. - Hydraulic Test Program - Component Locations Model 170

Description

Brand, model, etc.

Graduated beaker (0.5 liter, 10 ml graduations)

local purchase

 Risk of personal injury

Risk of personal injury (pinching/crushing) while working (loosening or removal) of pre-tensioned components. Use only approved special tools, tensioning devices, stops etc. in order to prevent serious injury. Visually inspect special tools for proper condition/function and possible damage prior to use. When using spring compressor tools, it is important that the spindle is not used in a damaged condition, that the threads are clean and proper. The spring plates are to be straight and not bent in any fashion. Note the assembly location of each spring plate and that the tightening nut threads are complatible and clean to the spindle. Do not use an impact tool to loosen or tighten the spring compressor tool nut. Wear safety gloves.

Risk of personal injury (pinching/crushing) while working on partially opened retractable hardtop. The rest mode is the interruption of the opening or closing sequence of the retractable hardtop, if the switch (S84) is released while being used to open or close the hardtop.



The rest mode holds the partially opened or closed retractable hardtop in this position for 7 seconds, thereafter the system is de-pressurized and depending on the position, the hardtop will come to rest upon itself. The danger of personal injury (pinching/crushing) exists if the work that is being carried out without first using the special tools to safely support the hardtop. Please review and use the special tools as mentioned in  33

Risk of personal injury (pinching/crushing) and in extreme cases loss of limbs or fingers, while working with components that are actuated either by hand, electrically via motors, hydraulically or pneumatically via connecting mechanical components, by reaching into moving components or mechanical units.

It is important that limbs, fingers and body parts be kept away from the operating areas of the moving components, especially if the components are actuated via the HHT or directly via circuit 30. Ensure that the test cables are of proper length, to prevent entanglement.

Keep clear of the retractable hardtop frame and linkage, upper part of the winshield and trunk lid during any retractrable hardtop operation.

Before begining the test, check the oil level in the hydraulic unit reservoir and top up if needed (refer to the Maintenance Manual).

In order to make accurate visual inspection for oil loss from the hydraulic system, the trim panels covering the hydraulic components must be removed.

The front latch can be locked or unlocked using the special tool provided with the vehicle for manual hardtop operation. The trunk can be unlocked using pull cables (refer to Owners Manual).

The hydraulic circuits and components for each operation of the hardtop can be tested separately.

Lastly, it is important to wear safety gloves when performing the tests.

Notes for Hydraulic Test:

The following jobs are the same for all test steps:

A. Connection of test equipment to hydraulic unit (Figure 3).

B. Test the hydraulic cylinders only at the piston's end position (prevents movement).

C. If the hydraulic lines need to be disconnected during pressure tests, the appropriate end position of the hydraulic cylinder must be first ensured.

D. All necessary hardtop positions can be achieved by pressing the retractable hardtop switch (S84) or by pulling the hardtop manually (Ignition: OFF).

In order to move the retractable hardtop manually, the emergency

operation relief valve on the hydraulic unit must be open all the way to a stop position using the allen wrench provided with the vehicle, refer to "N" in Figure 3). The emergency operation relief valve must be then closed (tightening torque approx.: 3 Nm).



The emergency operation relief valve can only be open with retractable hardtop closed or in open/stored position and with the ignition switch in OFF. If this is not adhered to, the seal on the valve could be damaged, which would in turn hinder building up the operating pressure in the hydraulic system.



The hydraulic cylinders (3 and 4, Figure 8) will lose all the pressure during manual movement of the retractable hardtop. If the hardtop is in the closed position, the retractable hardtop switch (S84) must be pressed toward front (close) for 5 sec. in order to build up the pressure in the cylinders again.

If the hydraulic cylinders are without hydraulic pressure and the retractable hardtop switch (S84) is pressed towards back (open position), the retractable hardtop will open rapidly. This could cause damage to the hardtop itself and to the components in the trunk/storage area.

Releasing the test pressure.

If the retractable hardtop comes to the end position (open/stored or closed) by pressing the retractable hardtop switch, the hydraulic pressure must be released from the system before disconnecting any hydraulic lines. To achieve that, the ignition switch must be in the OFF position and the relief valve on the hydraulic unit ("N", Figure 3) must be open all the way to the stop position. The pressure should drop in a short time, as observed on the pressure gauge. Place a shop towel around the hydraulic lines to be disconnected to avoid hydraulic oil spills when removing hydraulic lines. Additionally the ports must be plugged off using the necessary plug. The removed hydraulic lines should be placed in a container as well.

For plugging the entry ports on the hydraulic unit during the

pressure tests, the plugs - part number 129 589 00 91 01 must be used.

To use the pressure gauge after setting the hardtop to the desired

position at the test steps  2.0, 3.0, 5.0, 5.1, 5.2, 7.0, 7.1, 8.0, 8.1, 8.2, 8.3, 8.4, the trunk lid must be open via turnk lid lock and the rotary latch moved (using a small screwdriver) to a locked position. Before closing the lid, the rotary latch open position must be restored by pressing the lock button.
If hydraulic components need to be replaced, the disconnected hydraulic lines must be plugged with plug 129 589 00 91 07, while the ports on hydraulic unit must be plugged immediately using plug 129 589 00 91 11 to prevent the possible entry of dirt.

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

Test scope

Test connection

Test condition

Nominal value

Possible cause/Remedy

1.0

Checking retractable hardtop hydraulic

unit (A7/5)

(Figure 9)

Connect pressure gauge according to connection diagram (Figure 3).

Block retractable hardtop at the front latch with the retainer (part number 170 589 00 61 00). Refer to Figure 4 - Use of retainer.

Starting point:

Retractable hardtop

rests on the front

latches, trunk lid pivoted

towards rear.

Ignition: ON

Press and hold retractable

hardtop switch (S84) for

5 sec. in close position

(towards front).

Read test pressure:

180 - 200 bar

Check emergency operation relief valve (N)

Tightening torque: 3 Nm

<180 bar:

Replace retractable hardtop hydraulic unit (A7/5).

Nominal value O. K.

 2.0





Test scope

Test connection

Test condition

Nominal value

Possible cause/Remedy

2.0

Hydraulic circuit pressure test

(Figure 10)

Connect pressure gauge according to connection diagram (Figure 3).

N10-3



+ 22

Starting point:

Retractable hardtop completely open.

Trunk lid open, rotary latch on trunk lid lock locked.



Disconnect connector A on combination control module N10-3.

Bridge + terminal and pin

22 on the control module

connector with test cable

124 589 37 63 00

Set the bridge for 5 sec.

Read test pressure while the retractable hardtop hydraulic unit runs.

180 - 200 bar

< 180 bar:

 4.0.

Nominal values O. K.:

 3.0.